We just traded in our Mazda5 for a Pilot, and looked closely at the Highlander. Here are my pros/cons list:
Mazda5 is awesome to park and generally a tough little car. It was perfect for us w/2 small kids and occasional extra passengers, mostly driving in the city. The extra row is very tight; I'm 5'3" and could squeeze just fine but the climb into the seats was not fun for anyone who is larger than a small child. They stopped making the Mazda5 a few years ago but you could still find one used.
We were initially going to buy a Highlander to replace it, because we have a Rav4 and like Toyota. But the Highlander 3rd row was useless - it was literally no bigger than the Mazda5 despite being a much bigger vehicle. We don't need a 3rd row often, but it seemed silly to buy a larger car if we didn't have that functionality. So we bought a Pilot. The third row can fit my giant 6'2" teenager and there's a button that makes it easy to get in and out of. It's the same length as the Highlander (give or take an inch) and about 6" shorter than the Honda/Toyota minivans.
If you're really obsessed with size (I was) go to
https://www.cars.com/research/compare/ and you can enter various models/years and get all the dimensions.